Surface cleaning and defatting composition

ABSTRACT

LIQUID STORABLE CONCENTRATES AND CLEANING AND DEFATTING COMPOSITIONS, PARTICULARLY FOR METAL SURFACES, PREPARED FROM SAID CONCENTRATES BY DILUTION WITH WATER, WHEREIN THE CONCENTRATES COMPRISE A NONIONIC SURFACTANT, AN ALKANOLAMINE SALT OF A FATTY ACID AND AN ALKALOLAMINE.

United States Patent 3,663,445 SURFACE CLEANING AND DEFATTING COMPOSITION Horst Augustin and Siegfried Klussendorf, Mannheim,

Germany, and Konrad Kofer, Vienna, Austria, assignors to Lever Brothers Company, New York, N.Y. No Drawing. Continuation-impart of application Ser. No. 805,966, Feb. 24, 1969, which is a continuation-in-part of application Ser. No. 537,282, Mar. 25, 1966. This application Aug. 22, 1969, Ser. No. 852,478

Int. Cl. Clld 9/30 U.S. Cl. 252-117 6 Claims ABSTRACT OF THE DISCLOSURE Liquid storable concentrates and cleaning and defatting compositions, particularly for metal surfaces, prepared from said concentrates by dilution with water, wherein the concentrates comprise a nonionic surfactant, an alkanolamine salt of a fatty acid and an alkalolamine.

This application is a continuation-in-part of our copending U.S. application Ser. No. 805,966, filed Feb. 24, 1969 (now abandoned), which in turn is a continuationin-part of our U.S. application Ser. No. 537,282, filed Mar. 25, 1966 (now abandoned).

The present invention relates to surface-cleaning and defatting compositions, particularly for metal surfaces. They should be free from strong alkali and above all they should be capable of being prepared from a liquid storable concentrate by simple dilution with water.

The compositions of the invention have the advantage that they can be built up exclusively on an aqueous basis, i.e., free from organic solvents, which is particularly advantageous in cases in which a very active and yet mild defatting and cleaning composition is required, which must be free from organic solvents in view of waste water problems, fire and explosion risks, etc. It is also possible, however, to incorporate organic solvents, in particular hydrocarbons, into them, up to about 50% of the total mixture, the product being a clear, homogeneous solution which is miscible under all conditions and in any ratio with water. This results in such an improvement of the cleaning effect as to permit even the removal of combustion residues, such as oil soot, coal soot and other cracking products, which up to now could only be removed with highly toxic cleaning agents, such as phenols or chlorinated hydrocarbons.

There is a considerable interest in many branches of industry in such fully preformulated cleaning and defatting compositions, which after dilution with water remove soiling of an organic or inorganic nature from metal or plastic objects, equipment, machinery and tools, and which can also be used for the corresponding pretreatment of metal surface before these are subjected to certain processes. The industries referred to include, for instance, the metalworking, galvanic, engineening, light engineering and motor industries, as well as the radio gramophone and optical industries. The compositions in question should also fulfill the requirement that they are simple for less skilled workmen to use. They should permit the removal of metal .bore chips, polishing paste and other polishing agents, greases, lubricating oils, plastic particles, sand, traces of hand perspiration and other contaminations without in any way damaging metal surfaces or any lacquer or plastic coating present.

The compositions in question should be suitable for use in cleaning equipment, such as for instance immersion baths, flooding baths and spraying apparatus, in ultrasonic and steam jet equipment, in screening and centrifugal drums, as well as for the cleaning of objects and equipment by hand.

In view of their universal applicability, such cleaning and defatting compositions should be fully effective at high and low solution temperatures; they must not have a corrosive eifect and should be physiologically unobjectionable. When the working solution is heated, neither toxic nor inflammable vapors should develop. Also in industry no problems should arise with respect to the disposal of waste water when the compositions are used on a large scale.

Moreover, the cleaning compositions should be deliverable in as concentrated a liquid form as possible, for economy of transport and packaging and so as to permit the preparation of the working solutions by simple dilution, without loss of time in dissolving solid components. The concentrates must not separate out or change during storage. They should also remain stable in the face of fluctuations in temperature.

It will be evident that it is not easy to meet these many demands in one product. Difficulties particularly arise in reconciling the requirements as to cleaning and defatting efficiency with the requirements that the working solution should be capable of being prepared by simple dilution with water of liquid concentrates and these concentrates should have good storage properties in the face of fluctuations of temperature.

The invention relates to cleaning and defatting compositions which particularly in this respect fulfill the needs of technical practice better than those known to date, and which are distinguished both by an excellent cleaning effect and--in the form of liquid concentratesby particularly good storage properties. In addition, these concentrates are non-toxic; their solutions are non-corrosive, can be used without risk for manual cleaning and do not develop toxic or inflammable vapors, either in the cold or on heating. Spent solutions do not require any additional treatment before being discharged into the drainage systems.

The cleaning compositions according to the invention can be prepared from liquid concentrates by dilution with water and are characterized in that these concentrates are prepared from three active components in specific quantitative proportions. These active components are the following:

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(a) nonionic surface-active condensation products of about 3-15 moles ethylene oxide with an organic compound containing an active hydrogen bound to oxygen or nitrogen atoms;

(b) fatty acids;

(c) alkanolamines.

As explained hereinafter the ultimate concentrates and cleaning compositions contain the nonionic surfactant, the alkanolamine and the alkanolamine salt or soap of the fatty acid due to the reaction between the fatty acid and an excess of the alkanolamine under the mild temperature conditions used for preparing the concentrates.

The fatty acids used in preparing the concentrates should amount to at least 3% by weight, the nonionic surface-active condensation products should be used in at least double the amount of the fatty acids, and the alkanolamines used in at least 1.5-fold or preferably 3- fold molar excess with respect to the fatty acids, that 15, at least 2.5 moles or preferably 4 moles alkanolamine per mole fatty acid.

In the preferred embodiments of the invention, particularly if the compositions are to be free from organic solvents, the amount of fatty acid used in preparing the concentrates lies between approximately 3.5% and 15% by weight, the amount of nonionic surface-active substances used is about 20% to 45% by weight, and the molar ratio fatty acid; alkanolamine lies between 1:6 and 1:20. As far as the concentrates contain water, this should amount up to 50% by weight. The working solutions for cleaning and defatting use can be prepared from the concentrates by dilution with water in a concentrate to water ratio of 1: 10 to 1:200, preferably of 1:25 (parts by weight). In this connection no special demands are to be made upon the quality of the water. Corresponding to these dilution ratios, the water content in the solutions ready for cleaning and defatting use amounts to 91-99.75% by weight.

The nonionic ethylene oxide condensation products to be used in the liquid cleaning and defatting agents can be prepared in the conventional way by the addition of about 3-15 moles ethylene oxide to a basic compound containing active hydrogen. Such basic compounds may include substances containing hydroxylic, carboxylic and carbonamide groups. As nonionic addition products there can be used, for instance, the adducts of about 3-15 moles ethylene oxide to oxygen-containing compounds, such as alkyl phenols with 1-3 alkyl substituents, in which the sum of the carbon atoms of the alkyl radicals amounts to about 6-20, or primary, secondary or tertiary alcohols with 8-22 carbon atoms, or organic carboxylic acids with 8-22 carbon atoms. Also suitable are the corresponding addition products to nitrogen-containing compounds, such as carboxylic acid amides with 8-22 carbon atoms. Nonionic surfactants of the above types are further described in US. Pats. Nos. 1,970,578 to Schoeller et al., 2,174,761 to Schuette et al. and 2,213,477 to Steindorlf et al., the disclosures of which compounds are incorporated by reference herein.

Of the above-mentioned nonionic, surface-active addition products those substances are preferred which effect a particularly strong decrease in the surface-tension of the water, which have a good wetting effect and which are particularly capable of emulsifying fats, oils and waxes. Suitable products are, for instance, the addition products of 3-15 moles ethylene oxide with alkyl phenols, alcohols and fatty acid amides.

According to the invention, in compositions which, as concentrates, possess particularly good storage properties, combined with an excellent cleaning effect in the form of their diluted aqueous solutions, ethoxylated alkyl phenols are used with about 3-9 ethylene oxide moles per base molecule, in particular mixtures of nonyl phenols with about 5-6 and nonyl phenols with about 8-9 ethylene oxide moles. Very useful mixtures are also those consisting of a nonyl phenol condensed with 6 moles of ethylene oxide and a tridecyl alcohol condensed with about 15 moles of ethylene oxide. The use of mixtures of nonionic substances instead of a single substance in the compositions of the invention gives the advantage of a particularly broad range of action with respect to all kinds of soiling, together with a further increase in the storage stability of the concentrates. It is advantageous if the nonionic component with the shorter alkylene oxide chain is present in the mixture in predominant amount, i.e., exceeds the amount of the nonionic component with the longer alkylene oxide chain.

The fatty acid reactant to be used in preparing the concentrate may be saturated or unsaturated and contain 8-22 carbon atoms in the molecule, preferably 12-18 carbon atoms. It may be recovered from, for instance, natural fats of vegetable or animal origin. It is advantageous to use the more strongly hydrotropically-active long-chain fatty acids with 16-18 carbon atoms. Representative examples thereof include caprylic, capric, lauric, myristic, palmitic, stearic, arachidic, behenic, oleic, palmitoleic, linoleic, linolenic and elaeostearic acids. Mixtures containing oleic acid and, in particular, oleic acid itself are preferred.

"Particularly suitable as alkanolamines are short chain alkanolamines, for instance, mono-, diand triethanolamines, which may be used alone or in admixture.

It has surprisingly been found that the compositions prepared from nonionics, fatty acid and alkanolamines have an excellent cleaning and defatting effect, if the three components mentioned are employed in the ratios according to the invention. The cleaning and defatting effect is considerably greater than could be expected on the ground of the separate components present in the final compositions. In this connection it is essential that the composition be prepared from a high amount of nonionic surface-active substances and that the alkanolamines are used in a considerable excess in relation to the fatty acid. Only then also is the required storability of the concentrates obtained.

With the aid of the combination according to the invention, however, it is also possible to introduce into a specific mixture organic solvents which are water-insoluble per se, such as e.g., paraflin oil, diesel oil, petroleum, and thus achieve a particularly improved cleaning effect. Such a cleaning composition permits the removal of combustion residues that are particularly difficult to remove, e.g., those from vehicle motor pistons, without the use of substances required up to now that are dangerous to health, such as phenols and cresols.

In the concentrates according to the invention and also in the cleaning solutions, if desired, additives commonly used in the cleaning of metals can be incorporated, such as rust inhibitors, water softening agents, passivization agents, for improving the soil-suspending power, etc.

The following compositions for preparing a few concentrates according to the invention will now be given below by way of example:

EXAMPLE 1 Percent Oleic acid 5 Nonyl phenol-6 moles ethylene oxide condensate 30 Triethanolamine 50 Sodium ethylene diamine tetraacetate 1.1 Water to 100%. Oleic acid:

Acid value-199-202 Iodine value--9l Titre4-6 EXAMPLE 2 Mixed oils fatty acid 3.5 Nonyl phenol-6 moles ethylene oxide condensate 21 Tridecyl alcohol-15 moles ethylene oxide condensate 7 Triethanolamine 26 Sodium ethylene diamine tetraacetate 1.35 Water to Mixed oils fatty acid 12-20 carbon atoms.

EXAMPLE 3 Oleic acid 8 Nonyl phenol-6 moles ethylene oxides condensate 20 Nonyl phenol-8 moles ethylene oxide condensate 14 Triethanolamine 25 Perfume 0.05 Water to 100%.

EXAMPLE 4 Oleic acid 5 Nonyl phenol-6 moles ethylene oxide condensate 12 Triethanolamine 15 Kerosene K 27 Citric acid 1.4 Water to 100%.

EXAMPLE 5 Oleic acid 5 Nonylphenol-S moles ethylene oxide condensate 10 Tallow fatty acid amide-11 moles ethylene oxide condensate 20 Triethanolamine 50 Water 15 The above concentrates according to the invention, were prepared by adding the required amount of alkanolamine to the fatty acid charge with stirring while the mixture was slowly heated to approximately 50 C. The heating was then stopped after which the other ingredients were incorporated with good mixing but without special precautions.

In view of the above procedure for preparing the concentrates of the invention, the alkanolamine component reacts in the classical process with the fatty acid component to form the alkanolamine salt or soap of the fatty acid and to leave unreacted excess alkanolamine in the final concentrates. Therefore, the final concentrates contain from about 6% to about 45% by weight of the nonionic surfactant, from about 4% to about 33% by weight of the alkanolamine salt of the fatty acid, from about 2% to about 90% by weight of the alkanolamine and from about to about 50% by weight of water.

EXAMPLE 6 This example, prepared as above, is included to show that compositions which contain the above three essential ingredients but in which the conditions according to the invention are not fulfilled have unsatisfactory storability performance.

Percent A B C Uleic acid 5 5 Triethanolamlne alkyl benzene sulfonate 10 1O Nonyl phenol-l0 moles ethylene oxide condensate 5 10 Nonyl phenol-6 moles ethylene oxide condensate 15 10 Trldecyl alcohol-15 moles ethylene oxide condensate 5 10 Triethanolamine 5 5 5 Isopropanol.. 10 10 Water To 100 These compositions were found to be unsatisfactory in storage stability and/or cleaning ability. The amount of triethanolamine is too low in proportion to the fatty acid present.

The following compositions, prepared as above, were also found to be unsatisfactory in storage stability and/ or cleaning ability. The content of nonionic is too low.

The following compositions, prepared as above, were also found to be unsatisfactory in storage stability and/ or cleaning ability. The content of fatty acid is too low.

Percent F G H J Olelc acid Nonyl phenol-3 moles ethylene oxide condensate Nonyl phenol-8 moles ethylene oxide condensate Nonyl phenol-6 moles ethylene oxide condensate 21 2t Nonyl phenol-15 moles ethylene oxide condensate 5 Trideeyl alcohol-15 moles ethylene oxide condensate 7 Trlethanolamine Isopropanol Water What is claimed is:

1. Liquid storable concentrates and cleaning and defatting compositions, particularly for metal surfaces, prepared from said concentrates by dilution with water, consisting essentially of:

(a) a nonionic surface active condensation product of about 3-15 moles of ethylene oxide with a basic organic compound selected from the class consisting 6 of alkyl phenols having a total of 6' to 20 alkyl carbon atoms, C to C alcohols, C to C carboxylic acids and C to C amides;

(b) the mono-, dior tri-ethanolamine salt of a fatty acid having from 8 to 22 carbon atoms;

(0) mono-, dior tri-ethanolamine; and

(d) from about 0% to about 50% by weight of water;

in which the amount by weight of nonionic surface active condensation product is at least double the amount of the fatty acid moiety of the ethanolamine salt, the molar ratio of the free ethanolamine to the fatty acid moiety of the ethanolamine salt is at least 1.5 :1 and the fatty acid moiety of the ethanolamine salt of a fatty acid is at least 3% by weight of the total composition.

2. Concentrates and cleaning compositions according to claim 1, which consist essentially of:

(a) from about 6% to about 45% by weight of the nonionic surface active condensation product;

(b) from about 4% to about 33% by weight of the ethanolamine salt;

(0) from about 2% to about by weight of the ethanolamine; and

(d) from about 0% to about 50% by weight of water.

3. Concentrates and cleaning compositions according to claim 1 wherein the nonionic surface active condensation product is a mixture of a condensate of nonyl phenol with about 56 moles of ethylene oxide and a condensate of nonyl phenol with about 89 moles of ethylene oxide, the condensate with the shorter ethylene oxide chain being present in a predominant amount of said mixture of nonionic surfactants.

4. Concentrates and cleaning compositions according to claim 1 wherein the nonionic surface active condensation product is a mixture of a condensate of tridecyl alcohol with about 15 moles of ethylene oxide and a condensate of nonylphenol with about 6 moles of ethylene oxide, the condensate with the shorter ethylene oxide chain being present in a predominant amount of said mixture of nonionic surfactants.

5. Concentrates and cleaning compositions according to claim 1 wherein said ethanolamine salt of a fatty acid is the triethanolamine salt of oleic acid and wherein the ethanolamine is triethanolamine.

6. Concentrates and cleaning compositions according to claim 1 which are free from organic solvents.

References Cited UNITED STATES PATENTS 2,466,632 4/ 1949 Borus 252-118 2,583,165 1/1952 Campbell 252-118 2,700,654 1/1955 Holman 252-118 2,831,815 4/1958 Klisch 252-152 3,156,655 11/1964 Bright 252-109 2,874,126 2/ 1959 Epstein et al 252-152 3,222,201 12/1965 Boyle et a1 252-152 3,213,028 10/1965 Wood 252-89 3,352,695 11/1967 Iaciofano 252-89 OTHER REFERENCES Rainey et al.: Nonionic Surface Active Agents, Article in Chemical and Engineering News, vol. 31, No. 44, Nov. 2, 1953, pp. 4521-4523.

McCutcheons Detergents and Emulsifiers, 1967 annual, p. 262.

Union Carbide, Alkanolamines and Morpholines, 1960, pp. 8-9.

Union Carbide, Emulsions and Detergents, 1961, pp. 7 0-71.

Bennett: The Chemical Formulary, vol. XIII, 1967.

HERBERT B. GUYNN, Primary Examiner US. Cl. X.R. 

